Ronaldinho and Beckham collect star cards together. They have 45 cards, of which Beckham's star card is less than five-seventh of Ronaldinho's.
Solution: If Ronaldinho has X cards, Beckham has (5/7)x-3 cards.
x+(5/7)x-3=45
( 12/7)x=48
x=48 (7/ 12)
x=28
28 -3= 17 (Zhang)
A: Ronaldinho has a 28-star card and Beckham 17-star card.